2 Key Notes From Lab Handout Enzyme: Catalase (from beef liver)Substrate: H2O2 (hydrogen peroxide)Stop Reaction: use sulfuric acid (H2SO4)Quantify Amt. of H2O2 left: titrate in KMnO4(potassium permanganate)Baseline: Starting total amount of H2O2FOUR ways enzyme activity can be altered:Salt concentration (salinity)pH (acid/base concentration)TemperatureActivators & Inhibitors
3 Lab #3- Enzyme Catalysis w/Catalase Three Parts to the lab:Establish Baseline Amount of H2O2Uncatalyzed Decomposition of H2O2Time Trials w/Catalase to determine Rxn rateProcedure:10 ml H2O2 in a beaker1.0 ml (H2O or Catalase)10 ml 1 M H2SO4Mix wellTake a 5 ml sample and titrate in KMnO4Read Initial and final measurements on buretRecord Data
4 Uncatalyzed data Final reading: 11.2 ml Initial reading: 8.1 ml Amount of KMnO4: 3.1ml
5 Sample Data Set I Amt. KMnO4(ml) 10 sec 30 sec 60 sec 90 sec. 120 sec. Baseline4.4Final reading12.015.317.423.124.411.511.6Initial Reading7.821.310.6Amount KMnO4 used126.96.36.199.188.8.131.52Amount of H2O2 used0.21.12.32.184.108.40.206
6 Sample Data II Amt. KMnO4(ml) 10 sec 30 sec 60 sec 90 sec. 120 sec. Baseline3.4Final reading8.610.211.212.211.511.6Initial Reading6.1Amount KMnO4 used2.51.61.00.60.30.10.05(one drop)Amount of H2O2 used0.91.82.42.83.13.303.35
7 Conclusion Questions to Consider Determine the amount of H2O2 in moles using the chemical equation on pg. 22 and your amount of H2O2 after 180 sec.From Question #6, Choose two factors that can affect the rate of enzyme-catalyzed reaction of Catalase. Draw a predicted graph for each reaction.Name two organisms that could be used to determine the reaction rate of an enzyme.List two major sources of error and one suggestion on how to improve the lab. What would you do differently?